Evaluation and proposal of novel resectability criteria for pancreatic cancer established by the Japan Pancreas Society

Background: The guidelines for the classification of the resectability of pancreatic cancer established by the National Comprehensive Cancer Network can be difficult to utilize in clinical practice. We evaluated novel criteria proposed by the Japan Pancreas Society.

Methods: We analyzed 382 patients with pancreatic cancer between 2001 and 2015 for survival differences among subgroups classified according to the Japan Pancreas Society classification. Overall survival and disease-free survival were expressed as median values and compared with data based on the National Comprehensive Cancer Network classification, and differences in initial patterns of recurrence were analyzed.

Results: Overall survival times according to the Japan Pancreas Society criteria were 34.2, 29.7, 17.3, 14.3, and 15.8 months for the groups defined as resectable, resectable with portal vein invasion, borderline resectable with portal vein invasion, borderline resectable with arterial invasion, and unresectable by locally advanced disease respectively. The overall survival of the resectable group was better than those of the borderline resectable with portal vein invasion or borderline resectable with arterial invasion groups (P < .0001); however, the borderline resectable with portal vein invasion, borderline resectable with arterial invasion, and unresectable by locally advanced groups showed no differences in overall survival. The resectable group showed a tendency toward better survival than the resectable with portal vein invasion group (P = .058). The median overall survival times according to the classic 2012 National Comprehensive Cancer Network criteria were 30.5, 20.5, 15.8, and 13.8 months for the resectable, portal invasion, common hepatic artery and superior mesenteric artery invasion groups, respectively. Each survival curve was clearly separate. The borderline resectable with arterial invasion and unresectable by locally advanced groups exhibited high local recurrence rates (42.0% and 44.8%, respectively).

Conclusion: The Japan Pancreas Society criteria, which are simpler, predicted survival differences between the resectable group and the other subgroups. Our data suggest that cancer patients with borderline resectable pancreatic cancer (borderline resectable with portal vein invasion and borderline resectable with arterial invasion) can be managed as a single subset.